Exterior wall covering and support therefor



EXTERIOR WALL COVERING AND SUPPORT THEREFOR May 17, 1966 J. c. WARINGETAL 3 Sheets-Sheet 1 Filed Dec.

INVENTOR5 JAMES C.WAR|NG LESLIE A. FREAM ATTORNEYS ioe y 1966 J. c.WARING ETAL 3,251,168

EXTERIOR WALL COVERING AND SUPPORT THEREFOR 5 Sheets-Sheet 2 Filed Dec.

INVENTORS VI'I'I'I' 7 mam? ATTORNEY/S May 17, 1966 J. c. WARING ETAL3,251,168

EXTERIOR WALL COVERING AND SUPPORT THEREFOR 3 sheets sheet 5 Filed Dec.28, 1961 I N VENTOR S J A M E S C WARI NG LESLIE A. FREAM ATTORNEYSUnited States Patent 3,251,162; EXTERIUR WALL COVERING AND SUIPURTTHEREFOR James C. Waring, Richmond, Va, and Lesiie A. Fream, JefiersonCounty, Ky, assignors to Reynolds Metais Company, Richmond, Va acorporation of Delaware Filed Dec. 28, 1961, Ser. No. 162,807 13 @iaims.(6]. 52-460) This invention relates to rigid Wall coverings for existingWalls of a building. More in particular, it relates to a combination offurring strips, preferably of extruded metal, which can be attached tothe exterior of the existing walls of a building, panels which areattached toadjacent strips and mullion covers which can be frictionallycoupled with the strips in order to cover the strips and the edges ofadjacent panels. The assembly of metal furring strips, panels andmullion covers provides a continuous covering which is particularlyadapted to the remodeling of the unsightly exteriors of old buildings.

Wall coverings which comprise elongated extruded metal furring strips,frictionally coupled covers therefor and panel members between adjacentstrips are known in the prior art. A known construction, for example,provides an elongated extruded snap-on cover which is generally H-shapedin transverse cross-section and which has a prong projecting outwardlyfrom one of the legs of the H. The furring strip has a complementaryprongreceiving groove or slot into which the prong on the cover can bepressed and which then frictionally holds the prong in place. The twoslots formed by the spaces between the legs of the H loosely engage anedge of a wall panel which is thus supported along its upper and loweredges by two horizontal covers and along its side edges by two verticalcovers. This type of assembly suffers from the disadvantage that thepanels, not being rigidly attached to the furring strips are subject tovibration and distortion by, for example, the action of the wind. Inaddition, in this type of assembly the weight of the panels istransmitted to the furring strips through the friction couplings whichcould pull apart under the action of the wind. In addition, in this typeof assembly the panels must be sufficiently rigid and have sufiicientstrength to resist distortion from their own weight when placed in avertical position with their edges loosely resting in the slots of thecovers.

The system ofthe present invention diifers from the known constructionjust described in that the panels are rigidly supported along theiredges. This arrangement is particularly advantageous when metal meshpanels or other weak or flexible panels which are not self-supportingare employed. In addition the weight of the panels is borne directly bythe furring strips. In addition, in the present invention the mullioncovers may be readily removed and replaced with others of different sizeand shape without disturbing the panles and furring strips in order toproduce a variety of appearances to the wall covering. These advantagesare obtained by providing a furring strip, preferably of extruded metal,which is adapted to have the edges of adjacent panels rigidly securedthereto and a mullion cover which is adapted to be frictionally coupledto the furring strip after the panels have been secured.

It is therefore a primary object of the invention to provide anarrangement of extruded metal furring strips and frictionally coupledcovers therefor which permits panels to be rigidly supported along theiredges.

It is a further object of the invention to provide an arrangement ofextruded metal furring strips, and frictionally coupled covers thereforwhich permits panels to be secured directly to the inning strips.

ice,

It is a further object of this invention to provide a wall coveringwhich comprises extruded metal furring strips, frictionally coupledcovers therefor and panels which are strong and rigid.

It is a further object of this invention to provide an arrangement ofextruded metal furring strips, frictionally coupled covers therefor andpanels which permit the covers to be removed without disturbing thepanels or furring strips.

It is a further object of the invention to provide an arrangement ofextruded metal furring strips and frictionally coupled covers thereforwhich is particularly suited to the support of panels constructed ofexpanded metal mesh or other weak or flexible metal.

' These and other objects and advantages will become apparent to thoseskilled in the art upon reading the following detailed description ofthe invention taken in conjunction with the drawings in which:

FIGURE 1 is a perspective assembly view, partly cut away and partlyschematic, of a wall covering constructed in accordance with theinvention showing generally how the furring strips, panels and mullioncovers are applied to the exterior of a wall of an existing building;

FIGURE 2 is a transverse section through a furring strip, mullion covershowing the manner in which the strip is mounted on an existing wall.

FIGURE 3 is an exploded view of a junction between horizontal andvertical furring strips and mullion covers.

FIGURE 4 is a transverse section through a furring strip and a modifiedmullion cover.

FIGURE 5 is a perspective view of the furring strip and mullion cover ofFIGURE 4.

FIGURE 6 is a transverse section through a mullion cover and a modifiedfurring strip.

Referring now to the drawings there is shown a wall covering which isassembled from a plurality of extruded aluminum furring strips Italuminum mesh panels 12 and extruded aluminum mullion covers 14. As seenin FIGURE 1, the furring strips 10 are attached to the exterior of anexisting wall 16 of a building in spaced horizontal and verticalpositions so as to form a support grid parallel to and spaced from thewall 16 for the attachment of the panels 12 and mullion covers 14. Thewall covering may extend over any openings in the existing wall such asa window lid or it may leave such openings uncovered, depending on thedesired appearance and purpose of the Wall covering. Each space in thegrid of furring strips 10 is occupied by one of the panels 12 each ofwhich is fastened with screws 2i along its upper and lower edges to twospaced horizontal furring strips 1i) and along its side edges to twospaced vertical furring strips It). Each portion of a furring strip 10which defines a side, top or bottom of a grid space thus is fastened toand helps to support two adjacent panels which are slightly spaced fromeach other. Projecting through the space between each two adjacentpanels is one-half of a friction coupling, or snap-lock 22, which isintegral with the furring strip 10 to which the two adjacent panels 12are attached. A mullion cover 14 having the complementary mating half ofthe friction coupling, or snap-lock 22, projecting therefrom is firmlyheld by the projection on each furring strip.

The relative positions of the existing building wall 16, a furring strip10, panels 12, and a mullion cover 14 and the manner in which they areinterconnected is shown in FIGURE 2. An L-shaped angle clip 24 has oneleg secured in a vertical position to the existing wall 16 with agalvanized steel bolt 28 which passes through a hole 25 in the leg ofthe clip. The other leg of the clip extends horizontally from the wall16. A bolt 28 passes vertically through the horizontal leg of clip 24and portion 36 of a furring strip 10 and is provided with a nut 30. Oneor more spacing washers 32 are placed as needed between the horizontalleg of the angle clip 24 and the portion 36 of furring strip to aid inpositioning the furring strip 11 Portion 34 of the furring strip 10provides a flat surface parallel to wall 16 to which the edges of panels12 are fastened with self-tapping screws 20. Portion 34 is provided witha plurality of horizontally spaced holes 38 so that self-tapping screws20, which can be readily forced through the expanded aluminum of whichthe panels 12 are constructed, may be easily screwed into place. The useof expanded aluminum mesh panels 12 and self-tapping screws 20 isadvantageous because no preformed holes need be formed through the edgesof the panels and therefore no alignment of holes in panels and portion36 of the furring strips 10 is necessary. After the panels 12 areinstalled in the grid spaces formed by horizontal and vertical furringstrips 10, a mullion cover 14 is pressed into position on each furringstrip 10 and held there by engagement of the snap lock 22. If desiredspaced screws 42, shown in dotted lines in FIGURE 2, may be insertedthrough the mullion covers 14 into the furring strip to provide a morepositive coupling between these two elements.

Each furring strip 10 of FIGURES 1-5 is an elongated extruded aluminumstrip of uniform generally T-shaped cross-section throughout its length.A flattened portion forms the cross bar 34 of the T and a portionprojecting at a right angle along the center line thereof forms the body36 of the T. Each end of cross bar 34 is provided with a lip 35extending in a plane parallel to that of body 36 and in a directionopposite to that of body 36. Two spaced parallel rib projections 44extend at right angles from the side of the cross bar 34 which isopposite body 36 and define the retaining half of snap lock 22. Theouter end 46 of each projection 44 is of enlarged cross-section and isprovided along its lateral surface with a groove 48. The cross sectionof each groove 48 is formed by three flat surfaces; a first surface 50extends substantially parallel to cross bar 34 from the lateral surfaceof end 46 toward the center of end 46; a second surface 52 joins thefirst surface 50 at an obtuse angle and extends in a direction away fromthe cross bar 34; a third surface 54 makes a right angle with the secondsurface 52 and extends back to the lateral surface of end 46. Thelateral surface between this junction and the tip of end 46 forms aconvex surface 55.

Each mullion cover 14 of FIGURES l-3 and 6 is an elongated extrudedaluminurnstrip of uniform cross-section consisting of a shell portion 56and two spaced parallel legs 58 projecting therefrom which define theprojecting half of snap-lock 22.

The free end 66 of each leg 58 is of enlarged crosssection and isprovided with three flat surfaces 60, 62 and 64 which are complementaryto the engageable with surfaces 50, 52 and 54 of the groove 48 in end 46of projection 44. While the embodiments illustrated in the drawings showthe projecting half of snap lock 22 on the mullion cover 14 and thereceiving half on the furring strip, the location of the respectivehalves could be reversed, if desired. It should be understood also thatthe particular snap lock 22 illustrated is not critical and that othersimilarly acting snap locks could be employed. In FIGURES 2-6 the shellportion 56 of each mullion cover 14 is seen to consist of an outer bodyportion 68 which is parallel to cross bar 34 of the furring strip 10 andtwo parallel skirt portions 70 which extend from the outer portion 68toward the furring strip 10. The crosssectional shape of outer portion68 and skirt portions may be varied as desired (for example FIGURES 2and 6) to change the external appearance of the mullion cover 14. Thesize of outer portion 68 and skirt portions 71) may also be varied asdesired so long as these elements are large enough to effectively hidefrom view the edges of adjacent panels 12 which are fastened to thefurring strips 10.

FIGURE 3 shows the manner in which horizontal and vertical furringstrips 10 and mullion covers 14 are secured to each other at a junctionof horizontal and vertical pieces. The vertical furring strips 10 arecontinuous from top to bottom of the assembled wall covering and thehorizontal furring strips 10, which are shorter in length, are connectedat each end thereof a vertical furring strip 16 and indirectly to theend of an adjacent horizontal furring strip 10. In order to permit theseconnections to be made, the body 36 of each horizontal furring strip hasa portion 72 which extends longitudinally at each end of the fur-ring.strip beyond cross bar 34 and which is provided with a bolt hole 74transversely therethrough. Body 56 of vertical furring strips 10 isprovided with spaced bolt holes 76 transversely therethrough. Connectionbetween horizontal and vertical furring strips may be made by means ofL-shaped angle clips 78 having a bolt hole 80 through each leg and bolts82 (FIGURE 1). Two angle clips 78 are attached to opposite sides of body36 of a vertical turning strip by aligning a hole 80 through each angleclip 78 with one of the holes 76 in body 36 and inserting a bolt 28(FIGURE 2) therethrough. Holes 74 in the portions 72 of two adjacenthorizontal furring strips are aligned with holes 80 in the other legs ofangle clips 78 by positioning the upper surface of portion 72 in contactwith the lower sunfaces of the leg of the angle clips 78. The portion 72of horizontal furring strip 10 is of such length that when holes 70 and'80 are in alignment, the ends of cross bar 34 of the horizontal furringstrips albuts against the lateral surface of cross bar 34 on thevertical furring strip as seen in FIGURE 1. An L-shaped angle clip 84having a pair of holes 86 transversely through each leg thereof and alongitudinal slot 88 between the holes 86 of one leg is employed tofasten the junction of horizontal and vertical furring strips 10 to wall16. Slot 88 is of such length and width that body 36 of a verticalfurring strip 10 will readily slide into it so that the end of theslotted leg Will come into abutment with the cross bar 34. When angleclip 84 is in this position, holes 86 are in alignment with holes 74 inend portions 72 of the adjacent horizontal furring strips 10 and withthe holes 88 in angle clips 78. Bolts such as 86 are then insertedthrough holes 80, 74 and 86 to complete the junction. Bolts 26 are theninserted through holes 86 in the non-slotted leg of angle clip 84 tohold the junction to wall 16. Intermediate the junctions the horizontaland vertical furring strips 10 are secured to wall 16 with L-shapedangle clips 24 as already described With respect to FIGURE 2.

A modified mullion cover 14 mounted on a standard furring strip 10 isillustrated in FIGURES 4 and 5. In this modification the shell portion56 and leg portion 57 are separate pieces secured together. The legportion 57 is an extruded aluminum strip of uniform generally U-shapedcross-section having spaced parallel legs 59 which are identical to legs58 of the mullion cover 14 of FIGURES 1-3 and 6 except that each leg 59is provided with a lateral wing piece 94 extending at a right angle fromthe side thereof. The exterior surface of each leg 59 near the base ofthe U is provided with a groove 90 with the result that the portion ofthe U which joins the legs 59 together forms a flange 92. The shellportion 56 of the modified mullion cover 14 is an extnuded aluminumstrip having outer portion 68 and parallel skirt portions 70 similar toelements 68 and 70 of the mullion cover 14 of FIGURES l3 and 6. Wingpieces 94 on leg portion 57 and skirt portions 70 on shell 56 are ofsuch length that they abut one another along their adjacent edges. Theouter portion 68 of the modified mullion cover 14 is provided with acenter leg 94 projecting outwardly therefrom between the skirt portions70. The free end of leg 94 is of enlarged cross-section and has a groove96 therein which is complementary to and slidably engageable with flange92 on leg portion 57. To hold the flange 92 and groove 96 tightlytogether, spaced screws 98 are inserted through the flange 92 into thebody of leg 94. The leg portion 57 of the modified mullion cover 14serves as a connecting piece between a furring strip and the shellportion 56 of the cover and need not extend the entire length of thefurring strip 10. As seen in FIGURE 5, two leg portions 57 eachrelatively short in length, are spaced along a greater length of furringstrip 10. Leg portions 57 may be, for example, 6 inches in length andplaced 3 feet apart along the furring strip. If desired, however, legportion 57 may be made as long as the furring strip 10 and shell portion56 may be omitted entirely. When employed without a shell portion 56,leg portion 57 and particularly wing pieces 94 would serve to hide theadjacent edges of panels 12 from view.

A modified furring strip 10 is illustrated in FIGURE 6. The modifiedfurring strip consists of an extruded aluminum strip having a flatportion 100 and two spaced projections 44 extending therefrom. The outerends of the projections 44 are of enlarged cross-section and havelateral grooves 48 and convex tip surfaces 5 5 as described with respectto FIGURE 2. Spaced bolt holes 106 transversely through flat portion 100are provided so that the surface of flat portion .100 may be secured tothe wall of a building with bolts.

A suitable sequence of steps for assembling the furring strips 10 ofFIGURES 1-5 into a grid for supporting the panels 12 and mullion covers1 4 is apparent from the above description of the parts. Angle clips 24and 84 are first attached to wall 16 of a building at proper locationswith galvanized bolts 26. Vertical furring strips 10 may then beinserted into slots 88 in angle clips 84 and fas tened in place bybolt-ing to the projecting legs of angle clips 24 with bolts 28 and nuts30. The horizontal furring strips 10 are placed between adjacentvertical furring strips with extending end portions 72 resting on top ofthe projecting slotted legs of angle clips 84. Angle clips 78 are placedin position on end portions 72 so that holes 80 align with holes 76 inthe vertical furring strips 10 and with holes 74 and 86 in end portions72 and angle clips 84 respectively. Bolts 28 may then be insertedthrough the aligned holes and secured with nuts 30. It should beunderstood that the sequence of assembly steps is not critical and maybe varied as desired.

In assembling the modified furring strips 10 of FIG- URE 6 into a grid,angle clips 78 and 84 are omitted. The vertical modified strips arebolted through hole 106 directly to wall 16 and short lengths ofidentical strips are likewise bolted to the wall after being positionedhorizon- .tally between the vertical strips. No fitting of parts at thejunction of horizontal and vertical strip is necessary; the ends of thehorizontal strips merely abut with the edges of the vertical strips. Inpractice the modified furring strips 10 would be employed when wall 16of an extending building is sufficiently smooth and fiat to permit thefurring strips 10 to be attached without deforming them or subjectingthem to excessive stresses. Shims would normally be inserted betweenfiat portion 106 and the wall to allow space for the panel screws 20.

The attachment of expanded aluminum mesh panels 12 to crossbar 34 of thefurring strip of FIGURES l-S or flat portion 100 of the modified furringstrip of FIGURE 6 is readily accomplished with self-tapping screws 20.The screws 26 can be driven through the edges of the panels 12 intopreformed spaced holes 25. When the panels 12 are constructed of amaterial which cannot be penetrated by self-tapping screws, holes mustbe provided in the panels to allow the screws or other fastening meansto pass therethrough. The lips 35 projecting from crossbar 34 and fromflat portion 160 tightly engage the panels 12 as they are fastened inplace and aid in holding them against slippage.

The mullion cover 14 of FIGURES l3 and 6 is attached to a furring strip10 after the panels 12 have been installed by merely placing the coverparallel to the strip so that the ends 66 of legs 58 of the cover are incontact with the convex surfaces 55 of projections 44 on the strip andforcing the cover toward the strip to engage the snap lock 22 betweenthe two elements. As the cover 14 moves toward the strip 10, the ends 66of legs 58 of the cover slide over the convex surfaces 55 and arethereby forced slightly apart. As the movement continues surface 54 onthe end of the legs 58 passes off convex surface 55 and into engagementwith the surface 64 of groove 43. Legs 58 then snap toward each other sothat surfaces 54 and 52 thereof come into engagement with surfaces 60and 62 of groove 48. Surface 54 is thus held against surface 64. andfriction between the two holds the mullion cover 14 firmly to thefurring strip 16.

The modified mullion cover 1 of FIGURES 4 and 5 is mounted by attachingleg portions 57 to a shell portion 56 and then snapping that combinationonto a furring strip 10 in the manner described above. Each of aplurality of short leg portions are attached to a shell portion 56 bysliding flange 92 into groove 96 and inserting a screw 98 into suitablealigned holes drilled through the flange into leg 94 of the modifiedmullion cover. The leg portions 57 may be spaced from each other, asdesired, to provide suitable support to the shell portion 56. As alreadyindicated, a single portion 57 the same length as the furring strip 16may be snapped on. to the furring strip and the shell portion 56omitted.

The furring strips 1%! and mullion covers 14 are preferably formed ofextruded aluminum for several reasons.

The strips and covers being of uniform cross-section are- =readilyproduced by extrusion. In addition, aluminum is not only easily extrudedbut also has the properties of strength, weight corrosion resistance andpleasing appearance which are desirable in an exterior wall covering.Further, the softness of aluminum permits holes for assembling thepieces to be readily drilled and permits the use of self-tapping screwsfor ease in assembling the pieces. If desired, however, the strips andcovers can be formed of other materials such as steel or plasticdepending on such variables as size of the pieces and the re quiredstrength of the assembled covering.

The panels 12 are preferably formed of expanded aluminum mesh becausethis material is not only plea-sing in appearance but can be attached tothe furring strips 10 by self-tapping screws. The screws can be forcedmanually through the mesh and thusv do not require that holes bepreformed in the panels and aligned with holes in the furring stripsltl. However, the panels may be constructed of sheet metal or plastic ifdesired.

It is to be understood that the invention is not limited to the preciseembodiments described above and that modifications may be made withinthe scope of the invention.

What is claimed is:

1. In combination with the wall of a building: an open grid of elongatedfurring strips, each of said strips being a strip of uniform transversecross section and having a flat longitudinal portion facing outwardlyfrom said wall and further having adjacent said fiat portion aprojection forming one half of a snap-lock coupling; a panel oc cupyingat least one open space in the grid, at least one edge of said paneloverlapping the fiat longitudinal portion of an adjacent furring strip;a plurality of spaced securing means passing through said one edge andthrough the respective longitudinal flat portion; means attaching saidfurring strips to said Wall in a position such that said longitudinalflat portions are spaced outwardly from said Wall so that said securingmeans do not penetrate said wall; an elongated mullion covercorresponding to each furring strip, each of said covers having uniformtransverse cross-section; means forming a complementary one half of asnap-lock coupling associated with and projecting from each of saidcovers towards said furring strips and frictionally interlocked with theone half coupling on the corresponding furring strip, said mullioncovers having skirt portions extending toward, but spaced from, anypanel edge secured to the respective furring strip.

2. The combination of claim 1 wherein the flat portions of said furringstrips are provided with spaced holes for receiving said panel securingmeans and wherein said securing means include self-tapping screws forcedthrough the panel and into said holes in said furring strips.

3. The combination of claim '1 wherein said means attaching said furringstrips to said Wall include a plurality of bracket means fixed to saidwall and longitudinally spaced along said furring strips.

4. The combination of claim 1 wherein said furring strips and saidmullion covers are extruded aluminum and wherein said panel is expandedaluminum mesh.

5. The combination of claim 1 wherein the flat portion of said furringstrips has an outwardly projecting lip engaging the surface of the panelwhich overlaps the flat portion.

6. The combination of claim 1 wherein one of said snap-lock couplinghalves includes rib means projecting from and generally coextensive withits respective structure, said rib means having a single longitudinalgroove in each side defined by three generally flat intersectingsurfaces; and wherein the other of said snap-lock coupling halvesincludes a pair of legs extending from and generally coextensive itsrespective structure, said legs terminating in foot portions which arecomplementary to said grooves.

7. The combination of claim 1 wherein said furring strips are generallyT-shaped in transverse cross-section, the body of the T extending towardsaid wall and wherein the body on at least one of said furri'ng stripsextends longitudinally beyond the cross bar on the same furring stripand extends into close proximity with the body on another furring stripwhich extends at an angle to said one furring strip.

8. The combination of claim '1 in which at least one of said mullioncovers is detachable from the means forming the one half snap-lockcoupling associated therewith and wherein said means includes aplurality of longitudinally spaced! members of uniform transversecross-section.

9. A furring strip with attached snap-on mullion cover and wall panelcomprising: an elongated furring strip member of uniform transversecross-section, said member having a longitudinal flat surface andlongitudinal rib means projecting from said flat surface at generally aright angle, said rib means defining along its outer edges one half of asnap-lock coupling; a panel member secured along one edge to said fiatsurface adjacent said rib means; an elongated mullion cover of uniformtransverse cross-section; two leg means forming a complementary one halfof a snap-lock coupling associated with and projecting from said mullioncover toward said furring strip and frictionally interlocked with theone half coupling on said furring strip, said mullion cover having alongitudinal body portion overlying said one edge of said panel memberand a longitudinal skirt portion extending a substantial distance towardand spaced from said panel member; one of said snap-lock coupling halveshaving two grooves extending parallel to said furring strip and mullioncover and the other of said snaplock coupling halves having a pair ofspaced foot portions, each of which is complementary to and infrictional engagement with one of the grooves.

10. Apparatus as in claim 9 wherein each groove is defined by three flatsurfaces, one of the fiat surfaces of each groove being generallyparallel to the flat surface on said furring strip and intersecting withthe second flat surface at an obtuse angle, said second flat surfaceintersecting the third flat surface at about a right angle and whereinsaid third left flat surface merges with an outwardly convex surface atthe extremity of the one half coupling whereby said foot portions aredirected into their respective grooves.

-11. Apparatus as in claim 9 wherein said furring strip is generallyT-shaped in transverse cross-section, the top of the cross bar of the Tforming said longitudinal flat surface.

12. Apparatus as in claim 9 wherein said longitudinal flat surface ofsaid furring strip is provided with a lip extending toward said mullioncover and into engagement with said panel member.

13. A furring strip adapted to receive and frictionally engage a snap-onmullion cover comprising an elongated member of a genereally T-shapedtransverse cross-section, said member having a single body portion andsingle cross bar portion, the top of the cross bar portion of the Thaving a pair of centrally disposed spaced ribs extending therefrom in adirection away from the body portion of the T, the edge of each ribbeing of enlarged cross-section and having a single longitudinal groovein the outer surface thereof for receiving and frictionally engaging asnap-on mullion cover, each groove being defined by three flat surfaces,the flat surface nearest the cross bar portion of the T being generallyparallel to said cross bar portion and intersecting with the second flatsurface at an obtuse angle, said second flat surface intersecting thethird flat surface at about a right angle and wherein said third flatsurface merges with an outwardly convex surface at the extremity of therespective rib.

References Cited by the Examiner UNITED STATES PATENTS 1,522,708 1/1925Andrews 52 4s1 1,547,224 7/1925 McLean 52-481 2,998,112 8/196 1 Burgin52 495 3,053,353 9/1962 Miller 52-477 FOREIGN PATENTS 202,340 7/1956Australia.

RICHARD W. COOKE 111., Primary Examiner.

1. IN COMBINATION WITH THE WALL OF A BUILDING: AN OPEN GRID OF ELONGATEDFURRING STRIPS, EACH OF SAID STRIPS BEING A STRIP OF UNIFORM TRANSVERSECROSS SECTION AND HAVING A FLAT LONGITUDINAL PORTION FACING OUTWARDLYFROM SAID WALL AND FURTHER HAVING ADJACENT SAID FLAT PORTION APROJECTION FORMING ONE HALF OF A SNAP-LOCK COUPLING; A PANEL OCCUPYINGAT LEAST ONE OPEN SPACE IN THE GRID, AT LEAST ONE EDGE OF SAID PANELOVERLAPPING THE FLAT LONGITUDINAL PORTION OF AN ADJACENT FURRING STRIP;A PLURALITY OF SAPCED SECURING MEANS PASSING THROUGH SAID ONE EDGE ANDTHROUGH THE RESPECTIVE LONGITUDINAL FLAT PORTION; MEANS ATTACHING SAIDFURRING STRIPS TO SAID WALL IN A POSITION SUCH THAT SAID LONGITUDINALFLAT PORTIONS SPACED OUTWARDLY FROM SAID WALL SO THAT SAID SECURINGMEANS DO NOT PENETRATE SAID WALL; AN ELONGATED MULLION COVERCORRESPONDING TO EACH FURRING STRIP, EACH OF SAID COVERS HAVING UNIFORMTRANSVERSE CROSS-SECTION; MEANS FORMING A COMPLEMENTARY ONE HALF OF ASNAP-LOCK COUPLING ASSOCIATED WITH AND PROJECT-